The agency won the business following a pitch against the incumbent, Starcom MediaVest Group.
MPG's appointment follows what Sightsavers described as a "five-year standard review" of its offline media buying. The agency will take over the account from September and will focus on buying for DRTV and insert activity.
Sightsavers, an international development charity that works across Africa and Asia to combat and cure blindness, uses its advertising activity to encourage donations via its 24-hour phoneline or website. It also provides education and counselling services.
Maxine Angel, the recruitment marketing manager at Sightsavers, said: "MPG's strong credentials and pitch convinced us that it was time to move our media buying work."
The appointment of MPG follows changes in the marketing department at Sightsavers earlier this year. Sue Adams was appointed as the charity's head of marketing to replace Neil Thorns, who left to join Cafod.